Conventional production processes of optically active α-fluorocarboxylate derivatives, which are the targets of the present invention, can roughly be separated into the following three, and their representative publications will respectively be cited.
There are disclosed 1) a process (Non-patent Publication 1) in which an optically active α-amino acid derivative is subjected to a deaminofluorination in a hydrogen fluoride/pyridine complex, 2) a process (Non-patent Publication 2) in which a racemic α-fluorocarboxylate derivative is subjected to an optical resolution through an asymmetric hydrolysis by enzyme, and 3) processes in which optically active α-hydroxycarboxylate derivatives are subjected to dehydroxyfluorination by various techniques. The production processes of 3) are related to the present invention, and there are 3-1) a process (Non-patent Publication 3) by DAST [(C2H5)2NSF3], 3-2) a process (Non-patent Publication 4) by a fluoroalkylamine reagent, and 3-3) a process (Non-patent Publication 5) in which the hydroxyl group is turned into a sulfonate group, followed by replacement with a fluorine anion (F−).
As dehydroxyfluorination reactions using perfluoroalkanesulfonyl fluoride, there are disclosed 4) a process (Patent Publication 1 and Patent Publication 2) in which a substrate having a hydroxyl group is subjected to a dehydroxyfluorination by a perfluoroalkanesulfonyl fluoride (RfSO2F; Rf represents a perfluoroalkyl group), such as perfluorobutanesulfonyl fluoride (C4F9SO2F), in the presence of a special organic base, such as DBU (1,8-diazabicyclo[5.4.0]undec-7-ene), and 5) a process (Non-patent Publication 6 and Non-patent Publication 7) in which a substrate having a hydroxyl group is subjected to a dehydroxyfluorination by perfluorobutanesulfonyl fluoride in the presence of an organic base, such as triethylamine [(C2H5)3N], and a fluorination agent, such as triethylamine tris(hydrogen fluoride) complex [(C2H5)3N.3HF].    Patent Publication 1: U.S. Pat. No. 5,760,255    Patent Publication 2: U.S. Pat. No. 6,248,889    Non-patent Publication 1: Tetrahedron Letters (GB), 1993, Vol. 34, No. 2, p. 293-296    Non-patent Publication 2: Organic Syntheses (US), 1990, Vol. 69, p. 10-18    Non-patent Publication 3: Journal of the Chemical Society, Perkin    Transactions 1: Organic and Bio-Organic Chemistry (1972-1999) (UK), 1980, Vol. 9, p. 2029-2032    Non-patent Publication 4: Nippon Kagaku Kaishi (JP), 1983, Vol. 9, p. 1363-1368    Non-patent Publication 5: Tetrahedron; Asymmetry (UK), 1994, Vol. 5, No. 6, p. 981-986    Non-patent Publication 6: Organic Letters (US), 2004, Vol. 6, No. 9, p. 1465-1468    Non-patent Publication 7: 227th ACS Spring National Meeting Abstracts, Mar. 28 to Apr. 1, 2004, ORGN 198, D. Zarkowsky et al. (Merck)